Your basket is empty.

Added to Basket

MAD BMW S58 3.5" Fat Boy Downpipes M2 M3 M4 G87 G80 G82 G83


Product CodeMAD-4047

Earn Reward Points: 489

Dollar Value of Points: $4.89

The MAD 3.5" S58 Fat boy is the largest BMW S58 catless downpipe on the market!

Upgrade from the stock S58 downpipes to the MAD 3.5" Fat Boy  S58 catless downpipes for maximum airflow, power, and sound!

Upgrade to the MAD BMW 3.5" Fat Boy  S58 downpipes to eliminate the backpressure caused by your stock catalytic converters. By upgrading to our downpipes, your turbos can now spool faster and achieve maximum power. As a bonus, your car will sound a lot nicer as well.

Expect up to a 30HP increase on a tuned BMW S58 with stock turbos, even more on cars with upgraded turbos.

The flex pipe Section will help reduce the stress and unwanted vibration from the downpipes.


  • Compatible with right-hand drive and left-hand drive vehicles
  • Smooth bends for maximum airflow without any drone
  • Up to 30HP increase on the stock turbos, even more on upgraded turbos
  • Lifetime warranty on defects and fitment
  • 90 day return period
  • All orders ship in 1-2 business days
  • Spot on fitment
  • Flex section


  • 2021+ BMW M3 G80
  • 2021+ BMW M4 G82 G83
  • 2023+ BMW M2 G87



Customer Reviews

This product hasn't been reviewed yet.

Write a review

Write Review

1 2 3 4 5

Verify you are a human

Please enter a valid email address.
This field is required.

© 2021